1. Field of the Invention
The present invention generally relates to electrically actuated lock mechanisms, including electric strikes. More particularly, the present invention relates to solenoid assemblies and coil assemblies therefor for use in such lock mechanisms. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Related Art
In high security areas such as banks, computer rooms, museums, etc., electrically actuated strikes and door locks are frequently employed. These devices can be of either the fail-secure or fail-safe type. In fail-safe electric strikes and door locks, a locking condition is attained upon energizing the electric lock mechanism and an unlocking condition is attained by deenergizing the electric mechanism. Thus, a power failure or the like results in an unlocked condition of the mechanism, i.e., fail-safe. Conversely, in fail-secure electric strikes and door locks, a locking condition is attained upon deenergizing the electric mechanism and an unlocking condition is attained by energizing the electric mechanism. Thus, a power failure or the like results in a locked condition of the mechanism, i.e., fail-secure.
In order to provide electrical actuation of the lock mechanism in both fail-safe and fail-secure locks, a solenoid actuator is electrically connected to a switched source of electricity, such as from a power supply and a control system, and is physically connected to a latch mechanism of the lock. The solenoid actuator includes a coil assembly and an associated plunger which is driven by the coil and which actuates the latch mechanism of the strike or lock. Selective application of electricity to the solenoid, thus, causes energization/deenergization of the solenoid actuator which, in turn, produces the desired functionality.
While the preferred application of the invention is for use in conjunction with electric strikes, examples of fail-safe and fail-secure locks employing a solenoid actuator of the type described above may be found in U.S. Pat. Nos., 4,557,121 and 4,579,376, both of which have been assigned to the assignee of the present invention. The contents of both of these patents are hereby incorporated by reference. While the locks shown therein offer superb functionality, those of ordinary skill will recognize that solenoids utilized with the fail-safe locks shown therein are of a different construction than those utilized with the fail-secure locks shown therein. Thus, the manufacture of these locks entails the manufacture of both types of solenoids. Naturally, this results in a substantial amount of duplicated effort and a concomitant increase in the cost of both types of locks for many reasons. It would, therefore, be desirable to provide a single solenoid actuator which is compatible with either type of lock or function.
Accordingly, there remains a need in the art for a solenoid actuator which overcomes the aforementioned deficiencies of the related art by offering compatibility with either fail-safe (push-type) or fail-secure (pull-type) lock mechanisms or actuators.
Additionally, there remains a need in the art for a solenoid actuator which overcomes the aforementioned deficiencies of the related art by providing a solenoid actuator which can be converted between a solenoid actuator for use with a fail-safe mechanism and a solenoid actuator for use with a fail-secure mechanism with a minimum of effort.